CN118043210A

CN118043210A - Three-dimensional tire sipe having variable cross-section

Info

Publication number: CN118043210A
Application number: CN202280066288.5A
Authority: CN
Inventors: Z·A·斯泰尔巴; A·S·安哥拉杰; S·B·盖尔
Original assignee: Bridgestone Americas Tire Operations LLC
Current assignee: Bridgestone Americas Tire Operations LLC
Priority date: 2021-10-01
Filing date: 2022-09-27
Publication date: 2024-05-14
Also published as: JP2024533745A; EP4408679A1; WO2023056238A1

Abstract

Various aspects of a tire having a three-dimensional tire sipe with a variable cross-section are disclosed. In one aspect, there is provided a tire having a sipe, the tire comprising: wherein the sipe is a three-dimensional sipe extending radially inward into the tire from a tread surface of the tire, wherein the sipe comprises a horizontal undulating portion having at least one horizontal midpoint portion and at least one horizontal peak portion, wherein the sipe comprises a radial undulating portion having a vertical amplitude VA1 in the at least one horizontal midpoint portion and a vertical amplitude VA2 in the at least one horizontal peak portion, and wherein the vertical amplitude VA1 is greater than the vertical amplitude VA2.

Description

Three-dimensional tire sipe having variable cross-section

Background

Tires for use on vehicles may include a tread characterized by sipes. The presence of sipes on the tread of a tire may create more surface edges that engage the road surface, which may increase traction under poor road conditions. For example, a tire tread that includes sipes may perform better than a tire tread that does not include sipes in icy, snowy, or wet road conditions. Likewise, the more sipes a tire has, the better traction it may exhibit under poor road conditions.

However, adding sipes to tire tread blocks can reduce block stiffness, which can lead to undesirable irregular wear patterns in the tire and reduced tire performance in dry road conditions (i.e., non-adverse road conditions). Increasing the number of sipes in a tire tread block may be related to a decrease in the stiffness of the tire tread block.

It may be desirable to form sipes having interlocking shapes to restore at least some of the stiffness lost in the tread block due to the increased number of sipes. It may be desirable to make the interlocking sipe as thin as possible in its interlocking region. This configuration can improve braking performance on dry surfaces. In addition, for tires having a deep tread depth, the sipe must be deeper (and thus the sipe blade higher) to achieve the desired performance enhancement. Accordingly, it may be desirable to manufacture sipe blades configured to form sipes as thin and/or as high as possible while maintaining the durability of the sipe blades within the tire mold.

What is needed is an interlocking tire sipe that is configured to provide adequate block stiffness and/or braking performance while allowing the sipe blade to be thin and/or high as desired while maintaining the durability of the sipe blade within the tire mold.

Disclosure of Invention

In one aspect, there is provided a tire having a sipe, the tire comprising: wherein the sipe is a three-dimensional sipe extending radially inward into the tire from a tread surface of the tire, wherein the sipe comprises a horizontal undulating portion having at least one horizontal midpoint portion and at least one horizontal peak portion, wherein the sipe comprises a radial undulating portion having a vertical amplitude VA1 in the at least one horizontal midpoint portion and a vertical amplitude VA2 in the at least one horizontal peak portion, and wherein the vertical amplitude VA1 is greater than the vertical amplitude VA2.

In another aspect, there is provided a tire having a sipe, the tire comprising: wherein the sipe is a three-dimensional sipe extending radially inward into the tire from a tread surface of the tire, wherein the sipe comprises a horizontal undulating portion having at least one horizontal midpoint portion and at least one horizontal peak portion, wherein the sipe comprises a radial undulating portion having a vertical amplitude VA1 in the at least one horizontal midpoint portion and a vertical amplitude VA2 in the at least one horizontal peak portion, wherein the vertical amplitude VA1 is greater than the vertical amplitude VA2, wherein the value of the vertical amplitude VA1 is between the value of the vertical amplitude VA2 and 1.50mm, and wherein the value of the vertical amplitude VA2 is between 0.00mm and the value of the vertical amplitude VA 1.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate various exemplary configurations and, together with the description, serve to illustrate various exemplary embodiments. In the drawings, like elements have like reference numerals.

FIG. 1A illustrates a plan view of a tread 100 including a three-dimensional sipe 120 having a variable cross-section.

FIG. 1B illustrates a plan view of the three-dimensional sipe 120.

FIG. 1C illustrates a cross-sectional view of the three-dimensional sipe 120 taken along the section A-A shown in FIG. 1B.

FIG. 1D illustrates a cross-sectional view of the three-dimensional sipe 120 taken along the section B-B shown in FIG. 1B.

FIG. 2A shows a cross-sectional view of a three-dimensional sipe 220 having a vertical undulating portion 236 with 1.5 radial cycles.

FIG. 2B shows a cross-sectional view of a three-dimensional sipe 220 having a vertical undulating portion 236 with 2.5 radial cycles.

Detailed Description

Tires that are not intended to run on dry, smooth surfaces typically include a tread pattern that includes at least one groove, at least one rib, and/or a plurality of tread blocks. A tire designed for running under severe conditions, including, for example, snow or ice conditions, may additionally include a plurality of sipes in its tread. The addition of sipes to a tire tread can create more surface edges in the tire tread for engagement with icy or snowy road surfaces.

Increasing the length of the sipe, such as providing a sipe with a three-dimensional pattern, may increase the amount and length of cutting edges that may be used to engage snow, ice, and/or wet road surfaces.

Providing the sipe with a three-dimensional pattern in at least one of a lateral direction of the tire and a radial direction of the tire may allow opposing walls of the sipe to at least partially engage one another in a high friction or locking manner to maintain a desired stiffness of the tire tread block or tire tread rib. Maintaining a certain level of stiffness in the tire tread may reduce or eliminate irregular wear patterns. Maintaining a certain level of stiffness in the tire tread may improve the stopping distance of the tire. Maintaining a certain level of stiffness in the tread of the tire may improve traction of the tire.

It may be advantageous to provide interlocking three-dimensional sipes that are as thin as possible in their interlocking regions. Thus, sipe thicknesses of 0.3mm or less (and thus sipe blade thicknesses) may provide advantageous results. Furthermore, sipe thicknesses (and thus sipe blade thicknesses) below 0.3mm may be more advantageous.

However, sipe blades for forming sipes having a desired traction while maintaining a desired block stiffness are typically made as thin as possible, which can lead to sipe blade durability problems.

Fig. 1A-1D illustrate a three-dimensional sipe 120 having a variable cross-section.

Fig. 1A shows a tire tread 100 having a tread surface 102 and at least one rib/block row 104, 106, 108, 110 separated by at least one groove 112, 114, 116. The at least one rib/block row 104, 106, 108, 110 includes at least one three-dimensional sipe 120. The at least one rib/block row 104, 106, 108, 110 may include at least one groove 118.

For uniformity, the X-axis is oriented in the circumferential direction of the tire, the Y-axis is oriented in the axial direction of the tire, and the Z-axis is oriented in the radial direction of the tire.

FIG. 1B illustrates a plan view of the three-dimensional sipe 120. Sipe 120 extends radially inward from tread surface 102. Sipe 120 may include a terminal end 122, which may be the axially outermost end of sipe 120. Sipe 120 may include a horizontal undulating portion 124. The horizontal undulating portions 124 are oriented between horizontal non-undulating portions 126 that extend to the terminal end 122.

The horizontal undulating portion 124 may form a wave at the tread surface 102, which may be a sine wave. The horizontal undulating portions 124 may alternatively be linear elements angled relative to each other and connected by curves/fillets. The horizontal undulating portion 124 of sipe 120 includes a horizontal peak portion 128 and a horizontal midpoint portion 130. In FIG. 1C, a cross-sectional view of the sipe 120 at a horizontal midpoint portion 130 (taken along section A-A) is shown, while in FIG. 1D, a cross-sectional view of the sipe 120 at a horizontal peak portion 128 (taken along section B-B) is shown. These cross-sectional views of the sipe 120 include radial undulating portions 136 having different vertical amplitudes VA1, VA2, as further described below.

The horizontal undulating portion 124 may have a surface thickness TS. The surface thickness TS may range between a value of the internal thickness TI (see fig. 1C and 1D) and 1.50 mm. The surface thickness TS may be between 0.05mm and 1.50 mm. The surface thickness TS may be 0.60mm.

At least a portion of the horizontal non-undulating portion 126 may intersect the grooves 112, 114, 116, and wherein the horizontal non-undulating portion 126 may include a sipe thickness equal to the surface thickness TS throughout the radial depth of the sipe 120. The terminal ends 122 may include a sipe thickness equal to the surface thickness TS throughout the radial depth of the sipe 120.

The horizontal undulating portion 124 may have a horizontal period HP. The horizontal period HP may be between 4.50mm and 15.00 mm. The horizontal period HP may be 7.50mm, 6.64mm or 10.40mm.

The horizontal undulating portion 124 may have a horizontal amplitude HA. The horizontal amplitude HA is measured from the centerline of the sipe 120 at the horizontal peak portion 128. The horizontal amplitude HA may be between 1.50mm and 3.50 mm. The horizontal amplitude HA may be 2.40mm or 2.11mm.

The horizontal undulating portion 124 may have a horizontal angle A1 measured between a centerline of the sipe 120 (e.g., a line parallel to and extending longitudinally down the middle of the horizontal non-undulating portion 126) and a centerline of the horizontal midpoint portion 130. The horizontal angle A1 may be between 35 degrees and 55 degrees. The horizontal angle A1 may be 45 degrees.

FIG. 1C shows the sipe 120 taken along the section A-A shown in FIG. 1B, and FIG. 1D shows the sipe 120 taken along the section B-B shown in FIG. 1B. Sipe 120 may include a radially outer portion 132 that may include inclined walls that transition between a surface thickness TS and an inner thickness TI, or parallel walls (where ts=ti). Sipe 120 may include a radially inner portion 134 that may include an inclined wall that transitions between an inner thickness TI and a base thickness TB, or a parallel wall (where ti=tb). Sipe 120 may include a radially undulating portion 136 oriented between radially outer portion 132 and radially inner portion 134. The radially inner portion 134 may have a circular base.

The internal thickness TI may be between 0.05mm and the surface thickness TS. The internal thickness TI may be between 0.05mm and 1.50 mm. The internal thickness TI may be 0.15mm or 0.30mm.

The base thickness TB may be in a range between the value of the internal thickness TI and 1.50 mm. The base thickness TB may be between 0.05mm and 1.50 mm. The base thickness TB may be 0.60mm. The base thickness TB may be equal to the surface thickness TS.

The radial undulating portion 136 may form a wave, which may be a sine wave. The radial undulating portions 136 may alternatively be linear elements angled relative to each other and connected by curves/fillets.

The sipe 120 may have a total depth D between 4.50mm and 20.00 mm. The depth D may be 6.30mm, 6.80mm, 6.70mm or 11.18mm.

The first radially inward peak of the radially undulating portion 136 may have a depth P1 from the tread surface 102 of between about 1.20mm and 2.40 mm. The depth P1 may be 1.70mm.

The radial undulating portion 136 may include a vertical period VP. The vertical period VP may be between 1.60mm and 3.50 mm. The vertical period VP may be 2.30mm or 2.50mm.

Referring specifically to FIG. 1C and the sipe 120 at the horizontal midpoint portion 130, the radial undulating portion 136 may include a vertical amplitude VA1. The vertical amplitude VA1 may be between vertical amplitude VA2 and 1.50 mm. The vertical amplitude VA1 may be 0.82mm or 1.00mm. The vertical amplitude VA1 is greater than the vertical amplitude VA2.

Sipe 120 at horizontal midpoint portion 130 may include a radially undulating portion 136 having a radius R1. Radius R1 may be between 0.15mm and 1.50 mm. Radius R1 may be 0.15mm.

The radial relief portion 136 may have a radial angle RA1 measured between the sipe 120 (e.g., a line parallel to the radial, Z-axis) and a centerline of the sipe 120. The radial angle RA1 may be between radial angle RA2 and 45 degrees. The radial angle RA1 may be 41 degrees.

In the specific case of FIG. 1D and sipe 120 at horizontal peak portion 128, radial undulating portion 136 may include a vertical amplitude VA2. The vertical amplitude VA2 may be between 0.00mm and VA1. The vertical amplitude VA2 may be 0.23mm or 0.70mm. The vertical amplitude VA2 is smaller than the vertical amplitude VA1.

Sipe 120 at horizontal peak portion 128 may include a radially undulating portion 136 having a radius R2. Radius R2 is greater than radius R1. Radius R2 may be 0.63mm or 4.45mm.

The radial relief portion 136 may have a radial angle RA2 measured between the sipe 120 (e.g., a line parallel to the radial, Z-axis) and a centerline of the sipe 120. The radial angle RA2 may be between 0 degrees and the angle RA 1. The radial angle RA2 may be 13 degrees or4 degrees.

Between the horizontal midpoint portion 130 and the horizontal peak portion 128, the sipe 120 has a smooth, blended transition between the two sipe profiles shown in fig. 1C and 1D, where the vertical amplitude transitions between the vertical amplitudes VA1 and VA2 and back.

FIGS. 2A and 2B illustrate cross-sectional views of a three-dimensional sipe 220 having a vertical undulating portion 236 with 1.5 radial cycles (FIG. 2A) and 2.5 radial cycles (FIG. 2B). Sipe 220 may extend radially inward from tread surface 202 and may include a radially outer portion 232, a radially inner portion 234, and a radially undulating portion 236.

The radial relief portion 236 may include one or more full-cycle portions 240 and/or one or more half-cycle portions 242. The radial undulating portion 236 may include a period of between 1.0 and 8.0. The radial undulating portion 236 may include 1.5 cycles, 2.5 cycles, or 3.5 cycles.

The varying amplitudes (VA 1 and VA 2) as described herein may be used to improve the strength of the sipe blades used to make the sipes 120, 220 while allowing the thickness of the sipe blades (and sipes 120, 220) to be minimized regardless of blade durability. The sipe blades used to make the sipes 120, 220 can be made radially "taller" that achieves a deeper overall depth D regardless of blade durability. The sipe 120, 220 may exhibit an improvement in dry braking (2.5% improvement over prior art sipes) and an improvement in wet performance (2.0% improvement over prior art sipes).

To the extent that the term "includes" or "having" is used in either the detailed description or the claims, it is intended to be inclusive in a manner similar to the term "comprising" as "comprising" is interpreted when employed as a transitional word in a claim. Furthermore, to the extent that the term "or" (e.g., a or B) is employed, the term is intended to mean "a or B or both. When applicants intend to indicate "a only or B but not both", then the term "a only or B but not both" will be employed. Thus, the use of the term "or" herein is inclusive and not exclusive. See Bryan a. Gamner, A Dictionary of Modern Legal Usage, 624 (2d.ed.1995)). Furthermore, to the extent that the term "in … …" or "to … …" is used in the specification and claims, the term is intended to mean "on … …" or "to … …" in addition. To the extent that the term "substantially" is used in either the specification or the claims, it is intended to be inclusive of the accuracy achievable or reliable in manufacture. To the extent that the term "selectively" is used in the specification or claims, it is intended to refer to a condition of a component in which a user of the device can activate or deactivate a feature or function of the component as necessary or desired in use of the device. To the extent that the term "operatively connected" is used in the specification or claims, it is intended to mean that the identified components are connected in a manner that performs the specified function. As used in the specification and in the claims, the singular forms "a", "an" and "the" include plural referents. Finally, the term "about" when used in conjunction with a number is intended to include the number ± 10%. In other words, "about 10" may mean 9 to 11. The Cartesian coordinates referred to herein are intended to be in accordance with the SAE tire coordinate system.

As noted above, while the present application has been illustrated by a description of various aspects thereof, and while the various aspects have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Other advantages and modifications will be apparent to persons skilled in the art having the benefit of this disclosure. In its broader aspects, therefore, the application is not limited to the specific details, the illustrative examples shown, or any apparatus involved. Departures may be made from such details, examples and apparatus without departing from the spirit or scope of the general inventive concept.

Claims

1. A tire having a sipe, the tire comprising:

wherein the sipe is a three-dimensional sipe extending radially inward from a tread surface of the tire into the tire,

Wherein the sipe comprises a horizontal undulating portion having at least one horizontal midpoint portion and at least one horizontal peak portion,

Wherein the sipe comprises a radial undulating portion having a vertical amplitude VA1 in the at least one horizontal midpoint portion and a vertical amplitude VA2 in the at least one horizontal peak portion, and

Wherein the vertical amplitude VA1 is greater than the vertical amplitude VA2.

2. The tire of claim 1, wherein the vertical amplitude VA1 has a value between the value of the vertical amplitude VA2 and 1.50 mm.

3. The tire of claim 1, wherein the value of the vertical amplitude VA2 is between 0.00mm and the value of the vertical amplitude VA 1.

4. The tire of claim 1, wherein the thickness of the radial undulating portion is between 0.05mm and 1.50 mm.

5. The tire of claim 1, wherein the sipe comprises a radially outer portion intersecting the tread surface, wherein the thickness of the radially outer portion is greater than the thickness of the radially undulating portion.

6. The tire of claim 1, wherein the sipe comprises a radially inner portion, wherein the thickness of the radially inner portion is greater than the thickness of the radially undulating portion.

7. The tire of claim 1, wherein the radial undulating portion comprises a vertical period, wherein the vertical period is between 1.60mm and 3.50 mm.

8. The tire of claim 1, wherein the radial undulating portion comprises a period of between 1.0 and 8.0.

9. The tire of claim 5, wherein the sipe comprises a horizontal non-undulating portion oriented on each side of the horizontal undulating portion, and wherein the thickness of the horizontal non-undulating portion is equal to the radially outer portion thickness.

10. A tire having a sipe, the tire comprising:

Wherein the sipe comprises a radial undulating portion having a vertical amplitude VA1 in the at least one horizontal midpoint portion and a vertical amplitude VA2 in the at least one horizontal peak portion,

Wherein the vertical amplitude VA1 is larger than the vertical amplitude VA2,

Wherein the value of the vertical amplitude VA1 is between the value of the vertical amplitude VA2 and 1.50mm, and

Wherein the value of the vertical amplitude VA2 is between 0.00mm and the value of the vertical amplitude VA 1.

11. The tire of claim 10, wherein the thickness of the radial undulating portion is between 0.05mm and 1.50 mm.

12. The tire of claim 10, wherein the sipe comprises a radially outer portion intersecting the tread surface, wherein the thickness of the radially outer portion is greater than the thickness of the radially undulating portion.

13. The tire of claim 10, wherein the sipe comprises a radially inner portion, wherein the thickness of the radially inner portion is greater than the thickness of the radially undulating portion.

14. The tire of claim 10, wherein the radial undulating portion comprises a vertical period, wherein the vertical period is between 1.60mm and 3.50 mm.

15. The tire of claim 10, wherein the radial undulating portion comprises a period of between 1.0 to 8.0.

16. The tire of claim 12, wherein the sipe comprises a horizontal non-undulating portion oriented on each side of the horizontal undulating portion, and wherein the thickness of the horizontal non-undulating portion is equal to the radially outer portion thickness.